[Application of Vectra 3D facial imaging technology in orthodontic teaching program].

PURPOSE: To evaluate the effectiveness of Vectra 3D facial imaging technology in enhancing orthodontic teaching and training efficiency. METHODS: Thirty-two dental students, enrolled in 2014 as five-year and eight-year curriculum in School of Somatology, Air Force Military Medical University were selected as the subjects of this research. As an important teaching facility for training the students to practice orthodontic clinical examinations, 2D and 3D facial imaging systems were selected in this study for the students to collect and analyze the data relating to the facial complexion and appearance. The students were at first instructed to use the traditional 2D facial imaging system for 20 minutes, and then Vectra 3D facial imaging system for another 20 minutes. The students were required to deliberate on the specifically designed questionnaires to input their own assessment on these two modalities. The outcomes were quantitatively analyzed using SPSS 24.0 software package. RESULTS: As to the items 2, 5, 6 and 7 in the questionnaire, which indicated the following queries respectively: whether the use of imaging systems could inspire students' learning interest, whether the results drawn from these two imaging facial systems were accurate and reliable, whether the subjective bias were trivial , and whether these two imaging systems were feasible for orthodontic treatment appraisals. The results showed that there were significant differences in these four items between the two groups（P<0.05). As to the Items 1, 3 and 4 , namely, whether the acquisition of the teaching materials was an easy access, whether these two facial analytical regimes were beneficial for the students to obtain the new knowledge, and whether this specific teaching facility was easy for the students to manage, there was no significant difference between the two groups (P>0.05). CONCLUSIONS: Served as a new teaching syllabus facilitation, Vectra three-dimensional facial imaging system demonstrates a more satisfactory impetus for the students to learn than the traditional two-dimensional imaging system. Pragmatically, the analytical data resulted from the former remains more accountable than that of the latter.

[Clinical research on unilateral extraction for moderate crowding].

OBJECTIVE: To clinically investigate the results of unilateral extraction in the treatment of special moderate crowding cases. METHODS: 22 patients with harmonic profile and moderate crowding were selected and treated by unilateral extraction with Edgewise technique. The patients crowding was 6 - 9 mm and focused on one side of the arch. 22 patients with moderate crowding were treated by bilateral extraction as control. RESULTS: 22 patients have been treated successfully within 18 months. Crowding was completely resolved. Midline coincidence was basically maintained.Good intercuspation was achieved. There is no significant difference in dental arch symmetry between unilateral extraction and bilateral extraction (P > 0.05). CONCLUSION: Unilateral extraction can be successful in the treatment of special moderate crowding cases.